Electrical devices and devices containing multiple electrical components have become increasingly reliant on batteries for power. In many applications (e.g., automotive power systems, vehicle power systems, portable electronics, etc.), rechargeable batteries may be used. Such rechargeable batteries may include one or more batteries in a battery module, such as lithium-ion batteries, nickel-cadmium batteries, lead-acid batteries, and/or other battery types or combination of battery types. In an illustrative example, lithium ion batteries have become increasingly common in many applications, such as portable electronics, vehicular electrical systems, and the like. Advantages of lithium ion batteries include a favorable energy to weight ratio, no memory effect, a low rate of charge loss when not in use, and the like. In some applications (e.g., vehicular applications, industrial applications, aerospace applications, etc.), lithium ion batteries may be chosen based on the above mentioned attributes and/or for other reasons, such as a high energy density, a high power density, and the like.
In traditional recharging applications for Li-ion batteries, a one-step (e.g., constant current) or two-step (constant current/constant voltage) charging process may be used. In an illustrative example, a two-step process may include first charging the battery using a constant current (e.g., a current limit) until the volt limit has been reached (e.g., a cell voltage limit). Next, a maximum voltage per cell may be applied until the charging current falls below a threshold level, such as a multiple of a rated discharge current (Id) (e.g., 0.05*Id, 0.1*Id, 0.2*Id, etc.). For other battery chemistries, a same or different charging scheme may be utilized based on certain properties of the particular battery chemistry. For example, a lead acid battery may be charged by applying a constant voltage (e.g., a rated battery voltage) until the desired battery voltage has been reached.
In some cases, such as vehicular applications, industrial applications, etc., a battery charging system may be generator based. However, in some applications, the above-mentioned battery charging techniques may fail to efficiently charge batteries, or even may cause damage to battery modules because different environmental or electrical conditions may be overlooked. In other cases, a battery module may use mixed battery types, either as an intentional combination or an inadvertent combination. In such cases, a charging method for one battery type may actually damage or cause a failure of one or more components of the battery module. For example, a specialized battery charger may be used, but such use may increase costs associated with use of the battery module, increase weight of the battery module components and/or supporting equipment (e.g., the battery charger, etc.), increase system complexity (e.g., additional components that may be lost or damaged, etc.), and the like. As such, a need has been recognized for a generator-based system capable of efficiently charging a battery module without use of a separate battery charger.